I have been creating Balsamiq designs in some tickets, but have hundreds of tickets I've created across multiple projects. I want to be able to search just for the tickets that have the Balsamiq designs. I am able to create a query to search for attachments, but I also attach other types of files to tickets and don't want to look through them all.
What is the syntax to search for only Balsamiq attachments (.bmpr) files?